2.0Tfsi Fuel problems - engine dead

[Marklar]

Last week my 2.0 Tfsi engine cut out suddenly (fortunately while driving slowly on a side street), would not restart and I had to have the car recovered on a low-loader.

I did a scan with VCDS (I'm new to it so I'm still nervously feeling my way) and two engine faults were listed:

1) 012425 - Signal Line for Fuel Pump Electronics
P3089 - 002 - Electrical malfunction - Intermittent
Freeze Frame:
Fault Status: 00100010
Fault Priority: 0
Fault Frequency: 1
Reset Counter: 255
Mileage 96998 km
Time indication: 0
Freeze Frame:
RPM: 1309/min
Load: 30.2%
Speed: 0.0 km/h
Temperature: 8.0°C
Temperature: 3.0°C
Absolute Pres. 1020.0 mbar
Voltage: 14.097 V

2) 012555 - Low Pressure Fuel Regulation
P310B - 002 - Fuel Pressure Outside Specification
Freeze Frame:
Fault Status: 01100010
Fault Priority: 0
Fault Frequency: 1
Reset Counter: 255
Mileage: 97677 km
Time indication: 0
Freeze Frame:
RPM: 1314/min
Load: 76.8%
Speed: 20.0 km/h
Temperature: 54.0°C
Temperature: 20.0°C
Absolute Pres. 1010.0 mbar
Voltage: 13.43 V

I know Fuel Pump Control Modules are a frequent source of problems so I sourced another one (4F0906093L) second hand but nothing changed with it fitted. A subsequent scan showed the exact same information as above. The engine churns, sometimes initially fires for 2 or 3 seconds and then cuts out and dies.

I'm out of my depth here. Can anyone help with diagnosis please? I'm now suspecting that I need a new fuel pump but would like some confirmation before splashing out yet more money. Audi have quoted me £386.40 for pump 8E0919051CN plus £19.58 for a 'seal' plus £9.72 for a 'cap closure.' If I do have to fit a new pump, do I need these latter two items?

Any advice would be appreciated. Once the engine is running again I can continue trying to resolve my auto roof problems.

 

[Marklar]

Well, the fuel supply problem has finally been solved and in the process I have learned a very valuable lesson that I will pass on for everyone to share.

After fitting the second-hand fuel pump control module to no effect, I decided that the problem must be the in-tank lift pump so I ordered one from the dealer, fitted it and (you guessed) it made absolutely no difference. The engine would churn and churn but not fire. So I replaced the fuel filter - again no joy.

I was now at the point of having the car transported to the local VAG group specialist when a mate suggested that the problem could lie in the high pressure, cam driven pump whose cam follower I had changed some months ago.

Bingo! When we removed the pump, it was blocked with rubber particles from the fuel supply pipe. Here I should point out that earlier 2.0 Tfsi cars have a banjo joint on the HP fuel pump while later models like mine have a rubber hose secured to a ribbed brass spigot with spring steel clips. They are an absolute b****r to remove. Once the blockages were cleared, the engine started and ran faultlessly.

This afternoon I replaced the rubber hose (it's about 6 inches long) and while access is poor it is doable provided you remember to do lots of swearing.

And the big learning point? Resolving problems by replacing parts until you hit on the right one is a flawed and expensive approach. In all I spent in the region of £470 when the problem was a £6.60 fuel pipe.

You live and learn! Now my car is running beautifully again I can get back to getting the b****y roof working again.